(a) Technical Field
The present invention relates to a device and a method for calculating a distance to empty of an electric vehicle. More particularly, it relates to a device and a method for calculating a distance to empty of an electric vehicle capable of reducing an initial error in estimating a distance to empty of an electric vehicle.
(b) Background Art
The distance that can be traveled by a vehicle with the amount of the presently remaining fuel (e.g., the amount of gasoline, diesel, and LPG) is called a DTE (Distance To Empty).
The DTE provides important traveling information which provides convenience for drivers. The DTE is usually displayed on a trip computer included in many vehicles.
The DTE is very important information particularly for the drivers of electric vehicles. The batteries which operate these vehicles cannot be easily charged, and, thus, the DTE is one factor that requires accuracy.
Therefore, it is very crucial to reduce an early estimation error so as to improve accuracy of the DTE information.
The DTE varies greatly according to the driver's driving style, which cannot be measured but can only be estimated. The DTE of electric vehicles is the amount of electricity, i.e., the remaining capacity of a battery, unlike general vehicles (i.e. motor vehicles powered by fuel).
Therefore, there is a need for the development of a technology for estimating the remaining capacity of a battery to accurately estimate the DTE of electric vehicles, along with the development for a method of accurately estimating DTE.
Accumulated fuel efficiency (km/SOC hereinafter) for taking into consideration the driving inclination or style (e.g. speed, acceleration, deceleration, etc.) of a driver is measured to estimate the DTE. The accuracy of the accumulated fuel efficiency may be improved with the increase in the accumulation time, as the term hints. That is, it is possible to more accurately account for the driving inclination or style of a driver over time.
Unlike general vehicles, significant errors in the accumulated fuel efficiency are normally generated at an earlier traveling period of electric vehicles. In the case of general vehicles, it is easy to overcome these errors by use of various combinations of officially acknowledged fuel efficiency data and accumulated fuel efficiency. However, similar data and techniques have not been provided for electric vehicles, and thus the errors in the DTE information, particularly at earlier traveling periods, still remains to be solved.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.